Selective position read-off device for push-pull cable cores

ABSTRACT

A read-off device for a push-pull control cable. A barrel is anchored to the casing of the push-pull cable through a resilient attachment. The resilient attachment precludes axial movement of the barrel with respect to the casing of the push-pull control cable but permits gyration of the barrel with respect thereto. A plunger is slidably received within the barrel and a rod means connects the plunger to the core of the push-pull control cable, also preferably through a resilient attachment that precludes axial movement of the plunger with respect to the core but permits it to move axially with the core and gyrate with respect thereto. One or more tap members are selectively positionable along the barrel. The tap members carry buttons that are biasingly urged through selectively bored, diametric access apertures in the barrel for engagement with a contact on the plunger when the plunger is positioned therebetween so as to complete an electrical circuit therebetween, connection to which is accomplished through terminals on the tap member.

United States Patent [72] Inventor Richard D. Honk Stow, Ohio [21] Appl. No. 789,220

[22] Filed [45] Patented [731 Assignee Jan. 6, 1969 June 29, 1971 Morse Controls inc. Hudson, Ohio [54] SELECTIVE POSITION READ-OFF DEVICE FOR PUSH-PULL CABLE CORE-S 7 Claims, 6 Drawing Figs.

I 74/502, 200/166 CT [51] Int. Cl ..H01h 17/04,

HOlh 17/14 [50] Field of Search 200/161,

FOREIGN PATENTS 1,363,372 5/1964 France ABSTRACT: A read-off device for a push-pull control cable. A barrel is anchored to the casing of the push-pull cable through a resilient attachment. The resilient attachment precludes axial movement of the barrel with respect to the casing of the push-pull control cable but permits gyration of the barrel with respect thereto. A plunger is slidably received within the barrel and a rod means connects the plunger to the core of the push-pull control cable, also preferably through a resilient attachment that precludes axial movement of the plunger with respect to the core but permits it to move axially with the core and gyrate with respect thereto. One or more tap members areselectively positionable along the barrel. The tap members carry buttons that are biasingly urged through selectively bored, diametric access apertures in the barrel for engagement with a contact on the plunger when the plunger is positioned therebetween so as to complete an electrical circuit therebetween, connection to which is accomplished through terminals on the tap member.

PATENTED JUN29 m7:

SHEET 2 BF 2 em 5 N ATTOR N E Y5 SELECTIVE POSITION READ-OFF DEVICE FOR PUSH- PULL CABLE CORES BACKGROUND OF THE INVENTION The present invention relates to a position read-off device for push-pull control cables. Push-pull control cables are well known to the art as devices having a flexible core slidably reciprocable within a flexible casing and capable of transmitting mechanical motion by the application of either tensile or compressive forces to the core when at least the ends of the cable casing are satisfactorily clamped to permit relative motion between the core and casing.

Although the prior art knows many constructions for pushpull cable casings, one of the most suitable constructions to assure greatest flexibility and efficiency comprises a plurality of wires laid contiguously in a long pitched helical coil around the outer periphery of a plastic tube. The plastic tube comprises the innermost element of the casing and acts both as a bearing for the core slidably received therein and as a shield to protect the casing wires, particularly should all or a portion thereof be metallic, from any natural elements that might gain access to the interior of the casing along the core.

A flexible, plastic, outer cover similarly protects the wires as it maintains them in their cylindrical grouping around the inner tube.

Fittings are provided at each end of the casing to afford a means for securing the control cable in operative position.

The cable core, which reciprocates within the casing, acts as the working element that transfers mechanical motion between a controlling device and a remote, controlled device.

The applications for push-pull control cables are almost limitless, and many installations in which they are employed require precise determination as to the relative position of the cable core with respect to the casing as it reciprocates therein. Because of the manufacturing tolerances inherent not only in controlling devices and controlled devices but also in push pull control cables, the mechanism by which such precise determination is made must be fairly custom adapted to each installation. Prior read-off devices have been most unsatisfactory.

SUMMARY OF THE INVENTION It is, therefore, a primary object of the present invention to provide a device that permits precise, selective determination of the relative position of the cable core with respect to the casing for any installation.

This and other objects which will become apparent from the following specification are accomplished by means hereinafter described and claimed.

In general, a read-off device embodying the concept of the present invention is adapted for determining the relative axial position of a control cable core with respect to the control cable casing in which it slidably reciprocates. A barrel is anchored to one of the relatively reciprocable cable members and a plunger, slidably received within the barrel, is anchored to the other of the relatively reciprocable cable members. A tap member is selectively positionable along the barrel and carries opposed button means that biasingly extend through access apertures selectively located along the barrel. When the plunger moves between the buttons a contact, carried on the plunger, completes an electric circuit across the buttons. Access to this electrical circuit is accomplished through a pair of terminals on the tap member, one terminal being connected to each button.

To permit such a device to be used in conjunction with an extension tube gyrationally mounted on the end fitting of a cable casing and with an extension rod attached to the core and slidable within the extension tube, it is required that a resilient attachment, at least between the barrel and the casing, be employed. Such a resilient attachment must preclude axial movement of the barrel with respect to the casing yet permit gyration with respect thereto. It is also often desirable to utilize a similar resilient attachment between the core and the plunger so that while relative axial movement therebetween can be precluded gyration therebetween can be effected without binding the device.

One preferred embodiment is shown by way of example in the accompanying drawings and described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a read-off device embodying the concept of the present invention operatively mounted on a push-pull control cable;

FIG. 2 is an exploded perspective, partly broken away, depicting the device disconnected from the push-pull control cable;

FIG. 3 is a cross section taken substantially on line 3-3 of FIG. 1;

FIG. 4 is an enlarged view similar to FIG. 1 depicting the read-off device in longitudinal section with the plunger positioned in the barrel such that there is no electrical contact between the buttons of the tap member;

FIG. 5 is a partial area of FIG. 4 depicting the plunger positioned in the barrel such that an electric circuit is completed across the buttons of the tap member; and

FIG. 6 is an enlarged cross section taken substantially on line 6-6 ofFlG. 5.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring more particularly to the drawings a read-off device embodying the concept of the present invention is identified generally by the numeral 10 and is depicted operatively attached to a push-pull control cable 11.

The push-pull cable 11 may be of any conventional construction in which a core 12 slidably reciprocates within a casing, indicated generally by the numeral 13, to transmit mechanical motion by the application of either tensile or compressive forces to the cores 12 when at least the ends of the and is cold swaged, or otherwise suitably connected, onto the" exposed portion of the cylindrical grouping of wires 14. A plurality of ribs, not shown, may be provided within the end fitting 18 which, when crimped onto the outer cover 16, cf fects a seal between the end fitting 18 and the cover 16. The end fitting may be clamped in the desired position, as for example, by a bracket, not shown, that engages a retaining notch 19 in the outer periphery of the end fitting 18.

An end rod 20which is secured to the cable 12 in a wellknown fashion so as to become, in effect, an extension thereof-is received within an extension tube 21 that is gyrationally mounted on the end fitting 18.

The extension tube 21 not only guides the end rod 20 as it slides therein but also prevents excessive deflection of that portion of the core 12 that slides therein, particularly when subjected to compressive loads.

The gyrational mounting of the extensiontube 21 on the end fitting 18 is generally accomplished by a ball-and-socket arrangement, not shown, and is preferably protected by a resilient, sealing sleeve 22. A similar resilient sleeve 23 is also preferably positioned where the end rod 20 enters the extension tube 21.

The read-off device 10 has a barrel, or housing 25 mounted on the end fitting 18 by an anchor means 26. Specifically, a U- bolt 28 embraces the end fitting 18, and permissibly a portion of the resilient sealing sleeve 22, to assure a fixed position of the U-bolt 28 axially with respect to the end fitting 18. The fitting 18 may be provided with a second, annular retaining notch 29 into which the U-bolt 28 is received. The clamping element 30 for U-bolt 28 has a pair of sleeve portions 31 and 32 spaced laterally ofa web portion 33. The sleeve portions 31 and 32 are slidingly receivable over the spaced legs 34 and 35, respectively, of the U-bolt 28 so that by tightening nuts 36 and 37 the clamping element 30 will be forced against the fitting l8, and sealing sleeve 22, in cooperative opposition with the bight portion 39 of the U-bolt 28.

The web portion 33 is transversely bored, as at 40, to receive a resilient grommet 41. A bolt 42 extends through the grommet 41 and is anchored within a bore 43 in the base portion 44 of the barrel 25 to provide a resilient attachment between the anchor means 26 and the barrel 25 which precludes axial movement of the barrel with respect to the end fitting 18 and yet permits gyration with respect thereto.

Axially beyond the base portion 44, the barrel 25 has a relatively thin-walled portion 45 within which a slide member 46 reciprocates. The slide member 46 includes a plunger 48, the body portion 49 of which is electrically nonconductive and which carries a contact means such as the annular, electrically conductive, metallic ring 50. A plunger rod 51 is secured to the body portion 49 of the plunger 43 and extends axially within the barrel 25 and outwardly thereof through a bearing bore 52 in a plug 53 retained within the end of the thin-walled portion 45. As best shown in FIG. 4, the plunger rod 51 is insulated from the contact means 50, although the plunger 48 may be carried on the rod 51 between a shoulder 54 and a spaced flange 55. That portion of the plunger rod 51 extending axially beyond the plug 53 is secured to the end rod 20 by a cross head 56.

A first bore 58 through the crosshead 56 receives the end rod 20, the end rod being secured to the crosshead by a pair of embracing nuts 59 and 60. A resilient grommet 61 is received within a second bore 62 through the crosshead 56, and the plunger rod 51 is received through the grommet 61. The connection between the plunger rod 51 and the crosshead 56 being similarly achieved by a pair of embracing nuts 63 and 64 received on the threaded end portion 65 of the plunger rod 51. This provides a resilient attachment between the plunger rod 51 and the end rod 20 which precludes relative axial movement therebetween and yet permits gyration therebetween.

Accordingly, the resilient grommets 41 and 61, and to some extent the resilient sealing sleeve 22, permit the readoff device to swing, and therefore not bind, as the extension tube 21 gyrates with respect to the fitting 18 and yet maintains the barrel 25 axially fixed with respect to the cable casing 13 and the slide member 46 axially fixed with respect to the end rod forming an extension of the core 12.

One or more tap members 70 may be selectively positioned along the thin-walled portion 45 of the barrel to provide the desired read-off. Each tap member 70 has a body portion 71 with an annular bore 72 therethrough that is slidably en gageable with the radially outer surface 73 on the thin-walled portion 45 of the barrel 25. A pair of blades 74 and 75 extend outwardly of the body portion 71 in spaced relation and provide the terminals for an electrical connection.

Blade 74 is embraced by the body portion 71 and extends into a cavity 76 recessed radially of the bore 72 where it presents a button 78 resiliently biased radially inwardly of the bore 72. The blade 75 is also embedded within the body portion 71 and similarly extends into a cavity 79 recessed radially of the bore 72 where it presents a button 80 resiliently biased radially inwardly of the bore 72 in diametric opposition to but ton 78.

A pair of diametric access apertures 81 and 82 are bored through the thin-walled portion 45 of barrel 2 at precisely the location where the contact ring 50 will be when the position of thecore 12 with respect to the casing 13 makes a position read-off desirable.

With the access apertures 81 and 82 thus provided, the tap member 70 is located along the thin-walled portion 45 of the barrel 25 such that the buttons 78 and are biased through the apertures 81 and 82, respectively, toward a position radially inwardly of the interior surface 83 of the barrel 25, as shown in phantom on FIG. 6. To assure that the tap member 70 will be retained in the desired position a locking means is preferably employed. In the embodiment depicted, wherein both the barrel 25 and the body portion 71 of the tap member 70 are of an electrically nonconductive plastic material, a plug 84 of compatible plastic material, to which an adhesive has been applied, may be inserted through the radial bore 85 and against the thin-walled portion 45 of barrel 25 to join the two parts together.

Although any number of plastic materials will work quite satisfactorily, an acetal copolymer such as Celcon, by Celenese Plastics Company, provides an excellent material for the present readoff device. Celcons excellent flow characteristics and wide molding temperature range permit production of molded parts that are both free of polymer degradation and molded-in stress. Moreover, Celcon remains dimensionally stable over long periods of time and under varying conditions of use. In addition, Celcon is resistant to a very broad range of chemicals and possesses almost identical static and dynamic coefficients of friction.

The opposed ends on the body portion 49 of the plunger 48 present conical cam surfaces 86 and 88 to force the buttons 78 and 80 apart with the minimum resistance to the reciprocation of the plunger 48, and as the buttons 78 and 80 engage the contact ring 50 an electrical circuit is completed therethrough to effect the desired read-off.

- It should be appreciated that a plurality of tap members may be mounted on the barrel portion 45 to provide a plurality of read-offs. Moreover, inasmuch as the access apertures 81 and 82 are custom bored, the tap member 70 may be oriented as desired. For example, the tap member 70, shown in phantom on FIG. 4, may be oriented the same as tap means 70 or it may, with equal facility, be angularly displaced with respect thereto. In either event it should now be apparent that a device embodying the concept of the present invention accomplishes precise, custom read-ofi for one or more preselected positions of the push-pull cable core with respect to the cable casing in which it slidably reciprocates, and otherwise accomplishes the objects of the invention.

lclaim:

1. A read-off device for a push-pull control cable, the control cable having first and second relatively reciprocable members in the form of a core and casing, said read-off device comprising, a barrel, anchor means for mounting said barrel to a first relatively reciprocable control cable member, access apertures selectively located along said barrel, a plunger slidably mounted within said barrel and carrying a contact, connecting means for joining said plunger to the second of said relatively reciprocable control cable members, a tap member selectively positionable along said barrel, a pair of terminals on said tap member, a pair of button means carried on said tap member with one connected to each said terminal, said button means extending through said access apertures an electrical circuit being completed between said button means when they engage said contact.

2. A read-off device, as set forth in claim 1, in which a resilient attachment between said anchor means and said barrel precludes axial movement of the barrel with respect to the first relatively reciprocable control member and yet permits gyration with respect thereto.

3. A read-off device as set forth in claim 2, in which a resilient attachment between said rod means and the second relatively reciprocable control member precludes axial movement of said rod means with respect to the second relatively reciprocable control member and yet permits gyration with respect thereto.

4. A read-off device as set forth in claim 3, in which said button means are biasingly urged radially inwardly of said barplunger has a body portion, a contact ring being mounted thereon, oppositely directed, conical cam surfaces on said body portion, one on either side of said contact ring to engage and spread said button means against a biasing means.

7. A read-off device, as set forth in claim 1, in which locking means secure the tap member to said barrel.

22 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION ate 3 ,590, 196 Dated June 29 1971 Inventor(s) Richard D. Houk It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 42 change "cores" to read "core" Column 2, line 59, after "cable" insert ---core-- Column 3, line 72, change "barrel 2" to read "barrel 25" Signed and sealed this 23rd day of November 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents 

1. A read-off device for a push-pull control cable, the control cable having first and second relatively reciprocable members in the form of a core and casing, said read-off device comprising, a barrel, anchor means for mounting said barrel to a first relatively reciprocable control cable member, access apertures selectively located along said barrel, a plunger slidably mounted within said barrel and carrying a contact, connecting means for joining said plunger to the second of said relatively reciprocable control cable members, a tap member selectively positionable along said barrel, a pair of terminals on said tap member, a pair of button means carried on said tap member with one connected to each said terminal, said button means extending through said access apertures an electrical circuit being completed between said button means when they engage said contact.
 2. A read-off device, as set forth in claim 1, in which a resilient attachment between said anchor means and said barrel precludes axial movement of the barrel with respect to the first relatively reciprocable control member and yet permits gyration with respect thereto.
 3. A read-off device as set forth in claim 2, in which a resilient attachment between said rod means and the second relatively reciprocable control member precludes axial movement of said rod means with respect to the second relatively reciprocable control member and yet permits gyration with respect thereto.
 4. A read-off device as set forth in claim 3, in which said button means are biasingly urged radially inwardly of said barrel through said access apertures, said contact comprising an annular ring carried on said plunger
 5. A read-off device, as set forth in claim 3, in which a bearing bore is provided in said barrel oppositely of said anchor means, said rod means being slidably received within said bearing bore
 6. A read-off device, as set forth in claim 1, in which said plunger has a body portion, a contact ring being mounted thereon, oppositely directed, conical cam surfaces on said body portion, one on either side of said contact ring to engage and spread said button means against a biasing means.
 7. A read-off device, as set forth in claim 1, in which locking means secure the tap member to said barrel. 